SmCoO

SmCoO refers to samarium cobalt oxides, a family of mixed metal oxides in which samarium and cobalt occupy distinct lattice sites. The most studied member is SmCoO3, a perovskite-related oxide in which Sm3+ ions occupy the A-site and Co ions occupy the B-site within an ABO3 framework. This structure features networks of corner-sharing CoO6 octahedra and is sensitive to oxygen content and cation substitutions, which can modify the material’s electronic and magnetic properties.

In terms of chemistry, SmCoO3 and related compositions can exhibit Co in multiple oxidation states depending on oxygen stoichiometry, often resulting in mixed Co3+/Co4+ character and the presence of oxygen vacancies. Such nonstoichiometry and doping with other rare earths or alkaline earth ions are common ways to tune electrical conductivity, catalytic activity, and stability. Typical preparation methods involve solid-state reactions of precursor oxides or carbonates, followed by high-temperature annealing in air or oxygen; thin films and nanostructures are also synthesized for specialized applications.

SmCoO3-based materials are of interest as mixed ionic-electronic conductors at intermediate temperatures, with potential applications in catalysis and solid oxide fuel cell electrodes. They have been explored for oxygen reduction reactions, hydrocarbon reforming, and gas sensing. Challenges include maintaining phase purity and stability under reducing or low-oxygen conditions, as well as optimizing performance through doping, strain, and nanostructuring.

See also: perovskite oxides, rare-earth cobaltites, solid oxide fuel cells, catalysis.